GBA1 and Gaucher disease: Gaucher disease (GD, OMIM #230800, ORPHA355) is a rare, autosomal, recessive genetic disease caused by mutations in the GBA1 gene located on chromosome 1 (1q21) coding for the lysosomal enzyme glucocerebrosidase (GCase, also called glucosylceramidase or acid β-glucosidase 1, EC: 4.2.1.25) [1,2,3].